US4763093A - High-power pulse transformer for short high-voltage and/or high-current pulses - Google Patents

High-power pulse transformer for short high-voltage and/or high-current pulses Download PDF

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US4763093A
US4763093A US06/898,707 US89870786A US4763093A US 4763093 A US4763093 A US 4763093A US 89870786 A US89870786 A US 89870786A US 4763093 A US4763093 A US 4763093A
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winding
turns
pulse transformer
core
power pulse
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Hans-Jurgen Cirkel
Willi Bette
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Siemens AG
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Kraftwerk Union AG
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/09—Processes or apparatus for excitation, e.g. pumping
    • H01S3/097—Processes or apparatus for excitation, e.g. pumping by gas discharge of a gas laser
    • H01S3/0971—Processes or apparatus for excitation, e.g. pumping by gas discharge of a gas laser transversely excited
    • H01S3/09713—Processes or apparatus for excitation, e.g. pumping by gas discharge of a gas laser transversely excited with auxiliary ionisation, e.g. double discharge excitation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F30/00—Fixed transformers not covered by group H01F19/00
    • H01F30/06—Fixed transformers not covered by group H01F19/00 characterised by the structure
    • H01F30/10—Single-phase transformers

Definitions

  • the invention relates to a high-power pulse-transformer for short high-voltage and/or high-current pulses, preferably for high-power laser circuits, including at least one magnet core having self-enclosed magnet legs disposed around a central window and having two wide sides of the magnet core with axes being normal to the axis of the window, at least one undervoltage winding and at least one overvoltage winding wrapped around the magnet core and linked to the magnet core and to each other, the windings having turns of electrically insulated metallic conductors being substantially doubly-wound relative to each other.
  • Direct coupling, high-power, pulse engineering often does not succeed in matching the load resistance to the characteristic resistance of a pulse generating network. Furthermore, the switching elements which are capable of switching voltages and currents according to a given application, are often lacking.
  • pulse transformers which may also be referred to simply as pulse transformers, offers a possibility of circumventing such technical difficulties.
  • the possible functions of such devices are, inter alia: current matching, voltage matching, impedance matching, potential separation, and potential reversal.
  • a resonance transformer such as is described in publication (3) listed below, may be used.
  • the charging time of the pulse-generating network is several milliseconds. In order to achieve charging within a few ⁇ sec, it is necessary to employ a pulse transformer with a leakage inductance that is reduced to a minimum.
  • both the pulse-generating network and the switching element may be structured for the required X-ray tube acceleration voltage, as seen in publications (4), (5) and (6) listed below.
  • the disadvantage of these conventional devices lies in the required high dielectric strength of the components and the accompanying technological difficulties, especially at high repetition rates.
  • Another possibility for triggering an X-ray tube is to tap the supply pulse for the X-ray tube at the secondary side of a pulse transformer.
  • Descriptions of such devices can be found in publications (4) and (7).
  • difficulties are encountered when energies that are as high as possible are to be transformed in the shortest possible time
  • a very close coupling for reducing the internal voltage drop and the least possible leakage inductance are desirable. This necessitates minimization of the insulating spacings between secondary and primary windings and between the core and the windings, which leads to extremely high electrical field strengths because of the high voltages.
  • the general problem underlying the invention deals with overcoming the difficulties occurring in high-power pulse transformers according to publication (1) listed below, which further reduces the leakage inductance of the prior art, which avoids the corona effects or increases the dielectric strength and which improves the heat dissipation.
  • step-up transformer which generates pulses of higher voltages at optimal power transformation
  • step-down transformer which generates short pulses of very high amperage, while high-voltage pulses are transformed down and fed into a very low-resistance load. While the iron losses outweigh the copper losses in the step-up transformers, the losses in the conductors must be kept low in the step-down (current) transformers, by optimizing the winding cross sections;
  • a high-power pulse transformer for short, high-voltage and/or high-current pulses, preferably for high-power laser circuits, comprising:
  • a container having walls, a base plate disposed in the container, high-voltage leadthroughs disposed in the container walls, an insulating, cooling dielectric liquid disposed in the container, said dielectric liquid having a given heat transfer coefficient ⁇ [w/m m ⁇ K] with respect to an uncoated metal wall within the range of ⁇ 1 ⁇ 2 , said uncoated metal wall comprising by definition a metal wall being covered by a thin oxide or lacquer film within the ⁇ m-range, the influence of which on the heat transfer coefficient or on the dielectric properties of the couple "metal wall - dielectric liquid" being negligible;
  • the magnet core disposed on the base plate in the container, the magnet core having a central window formed therein defining an axis of the window and defining self-enclosed magnet legs disposed around the central window, the core having relatively wide sides normal to the axis of the window and relatively narrow sides;
  • At least one undervoltage winding and at least one overvoltage winding each being disposed in the dielectric liquid, being wrapped in each other around parts of the magnet core immersed in the dielectric liquid and being linked to the magnet core and to each other, the windings including turns of substantially mutually doubly-wound electrically insulated metallic conductors having a given thickness and having terminal winding ends disposed in the leadthroughs, the conductors having surfaces with a heat transfer coefficient ⁇ with respect to said dielectric liquid being within said range ⁇ 1 ⁇ 2 ; being higher than the the turns of each of the windings being self-supported or cantilevered and spaced apart from turns of the other of the windings by a first minimum spacing and being spaced from the magnet core by a second minimum spacing;
  • support insulators being partly disposed in the dielectric liquid and being adjacent and spaced from at least one of the sides of the magnet core by a third minimum spacing being greater than the sum of the second minimum spacing and the given thickness of the turns, at least the ends of the windings being secured in recesses formed in the support insulators;
  • the windings each being in the form of a winding helix and each being divided into smallest winding units each including at least one undervoltage winding and at least one overvoltage winding in the form of winding branches having mutually adjacent turns each surrounding an associated magnet leg and being mutually spaced apart by the first minimum spacing and being mutually parallel as viewed in axial direction of the winding helix;
  • the conductors of a given number of the smallest winding units of the undervoltage and overvoltage windings being connected to the support and terminal points for attaining a desired transformation ratio.
  • each one of the support insulators is associated with a respective wound magnet core leg or is associated with each respective wide side of the magnet core.
  • the support insulators are plate-shaped.
  • the winding ends of the smallest partial winding units formed of the winding branches of the undervoltage winding are supported by and connected to one of the support insulators, and the winding ends of the smallest partial winding units formed of the winding branches of the overvoltage winding are supported by and connected to another of the support insulators.
  • At least one of the windings carries high current and the conductor turns and the conductors are hollow and are cooled from the inside by a liquid coolant.
  • the secondary winding carries high current and is formed of parallel partial winding units having hollow conductor turns and conductors and the primary winding carries high voltage and is formed of mutually series-connected partial winding units formed of hollow turns and conductors.
  • the core is rectangular or may have a double U-shape or may have a UI-shape.
  • the core is annular or is oval.
  • the conductors are formed of a good conducting material having a specific resistance of 0.016 ⁇ [ ⁇ mm 2 /m] ⁇ 0.029 at 20° C. and the surfaces of the conductors have a structure within the band width which is bare metal with a thin oxide skin.
  • the conductors are formed of a good conducting material having a specific resistance of 0.016 ⁇ [ ⁇ mm 2 /m] ⁇ 0.029 at 20° C. and the surfaces of the conductors have a structure within the band width which is bare metal with a thin protective lacquer film.
  • All of the windings have self-supporting or cantilevered structures; this is understood to mean that the individual turns of the overvoltage and undervoltage windings, due to their suitable cross section, have sufficiently stiff or rigid spirals which retain their shape and are merely fixed or "secured” at the terminal ends of the smallest winding units on the support insulators without being supported by each other or by the core.
  • the insulation is formed of a dielectric liquid. Transformer oil or fluoridated hydrocarbon are suited for this purpose.
  • the windings and the magnet core, each of which are supported by separate support structures, are immersed in the fluid.
  • the dielectric or insulating liquid eliminates all problems dealing with the dissipation of the heat from the magnet core, from the dielectric itself and from the windings, such as by intrinsic convection or by forced circulation in a closed circuit equipped with a heat exchanger.
  • it presents no problem to attain high voltages while simultaneously using a compact construction because of the high insulating powers of the dielectric liquid.
  • Corona formation is prevented because the liquid sufficiently wets the conductors which are either bare or at most have a thin oxide film or protective lacquer film. Should a voltage spark-over nevertheless occur in the transformer, the liquid dielectric has a self-healing effect.
  • the cantilevered or self-supported construction facilitates a bifilar or doubly-wound configuration of primary and secondary windings (undervoltage and overvoltage windings), which is a prerequisite for least possible leakage inductance.
  • a suitable core material for the transformers is ferrite, for example.
  • FIG. 1 is a simplified, diagrammatic, cross-sectional view of the magnet core and the support insulators of a first embodiment of a high-power pulse transformer (hereinafter referred to as a pulse transformer for short) according to the invention, taken along the line I--I in FIG. 2, in the direction of the arrows;
  • a pulse transformer for short a high-power pulse transformer
  • FIG. 2 is a partially sectioned, front-elevational view of the device shown in FIG. 1;
  • FIG. 3 is a side-elevational view of the pulse transformer according to FIGS. 1 and 2 with one support insulator removed, which is partly sectioned along the line III--III in FIG. 2, in the direction of the arrows;
  • FIG. 4 is a greatly simplified front-elevational view of a second embodiment of the invention, showing only the magnet core and some of the smallest winding units; one leg of the transformer core being equipped with the three smallest coil units, each comprising two turns on the overvoltage or undervoltage side;
  • FIG. 5 is a view of the pulse transformer according to FIG. 1, physically assembled in a pulse-generating network in a Blumlein circuit with a thyratron as a high-voltage switch it being possible to connect an X-ray flash tube to the secondary side of the pulse transformer;
  • FIG. 6 is a schematic circuit diagram of the assembly according to FIG. 5, supplemented by an X-ray flash tube connected to the secondary side of the pulse transformer, including a spark gap indicated by broken lines, which serves as a rapid high-voltage switch, as an alternative to the thyratron:
  • FIG. 7 is a view similar to FIG. 3 of a third embodiment of the invention with a ring core pulse transformer:
  • FIG. 8 is a cross-sectional view taken along the line VIII--VIII in FIG. 7, in the direction of the arrows;
  • FIG. 9 is a cross-sectional view similar to FIGS. 1 and 8 of a fifth embodiment of the invention with a pulse transformer constructed as a current (step-down) transformer;
  • FIG. 10 is a fragmentary, partly sectioned view showing the oval magnet core and the cross-section of the winding conductors from above, taken along the line X--X in FIG. 9, in the direction of the arrows;
  • FIGS. 1-3 there is seen a self-supporting or cantilevered winding of a pulse transformer which is designated as a whole with reference symbol W, while a primary winding has symbol w 1 and a secondary winding has symbol w 2 .
  • the primary winding w 1 and the undervoltage winding are identical if a primary voltage u 1 is smaller than a secondary voltage u 2 , in which case the secondary winding and the overvoltage winding are also identical
  • This applies to a so-called voltage or step-up transformer whereas in a current (step-down) transformer, a higher voltage low current fed to the primary winding is transformed up into a low voltage higher current on the secondary side.
  • the primary voltage is the overvoltage and the secondary voltage is the undervoltage.
  • the self-supporting or cantilevered windings w 1 , w 2 each require a support structure, which is designated with reference symbol H as a whole, for a magnet core M1, for the primary winding w 1 for the secondary winding w 2 .
  • the magnet core M1 which is preferably a ferrite core, i.e a core made of highly-permeable material, is constructed as a rectangular core with closed magnet legs m1, m2, m3, m4 that are disposed around a central window 5, so that the two broad sides of the magnet core M1 (hereinafter referred to as the "core" for short) have axes which are normal to the axis 5.0 of the window.
  • the core M1 i.e. in this case its two legs m2 and m4, is surrounded by the above-mentioned winding W.
  • the primary winding w 1 and the secondary winding w 2 are each linked to the core M1 and to each other, and electrically insulated, metallic conductors 1 1 , 1 2 for turns w 01 of the primary winding w 1 and for turns w 2 of the secondary winding w 2 are largely bifilar or doubly-wound relative to each other
  • the primary and the secondary winding are identical with the undervoltage and overvoltage winding in a voltage transformer, and are therefore referred to hereinafter as O-winding and U-winding for short
  • the term bifilar or doubly-wound is understood to mean that the current paths of the winding conductors 1 1 , 1 2 turns w 01 , w 02 are so closely adjacent and parallel to each other that the magnetic leakage fields generated by currents flowing through them cancel each other out to the greatest possible
  • the conductors have a surface structure within the bandwidth which is metallically bare down to a thin oxide skin or a thin protective lacquer film.
  • the thin oxide skin (of aluminum conductors) or the thin protective lacquer film must not significantly impair the heat transfer from the metallic coil conductor to the liquid dielectric.
  • the dielectric strength of transformer oil is ⁇ 12 kV/mm. An oxide skin which is 1 ⁇ thick would then have a potential of 1 V. This precludes corona problems or the like which could occur with a solid, thicker dielectric.
  • the proportional field strength would be even smaller, because in each boundary surface of dielectric or electrically insulating layers, the electrical field strength suffers a jump in inverse proportion to the dielectric constant (DK). This means that the electrical field strength increases suddenly when the dielectric constant increases, and vice versa.
  • ⁇ temperature difference between liquid dielectric and the surface of the winding W 1 or W 2 in K.
  • the outer surface of the coil conductors may also have an anodization, a protective lacquer or the like, if the heat transfer coefficient ⁇ and/or the dielectric strength reach the required minima.
  • the individual turns W 01 , W 02 of the primary and secondary windings W 1 , W 2 are cantilevered or self-supporting, and are provided with a first minimum mutual spacing a between the turns W 01 -W 02 seen in FIG. 3 and a second minimum spacing b from the core M1 which they envelope, as seen in FIGS. 1 and 3. In the illustrated embodiment, a ⁇ 2 ⁇ b.
  • These minimum spacings a, b depend upon the field strength prevailing in the liquid dielectric, which will be discussed below, and upon the dielectric strength of the dielectric itself In addition, it is clear primarily from FIG.
  • Plate-shaped support insulators 1.1 and 1.2 which are designated in common with reference numeral 1, are disposed at a third minimum distance c from the core M1, and are adjacent at least one of the sides of the core M1; in the present case they are adjacent two wide sides m01, m02.
  • the third minimum distance c is greater than the sum of b+d, where d is the conductor thickness of the turns w 01 w 02 .
  • a practical value for c lies in the range (b+d) ⁇ c ⁇ 2 ⁇ (b+d), as may be learned from FIGS. 1 and 2, because in that case a good convection and/or forced flow can develop in the liquid dielectric for the purpose of cooling the windings in the space between the two support insulators 1.1 and 1.2.
  • a smallest winding unit w 0 is wound on each of the two legs m2 and m4 of the rectangular core M1 (the phrase "wound on” in this context means that the turns w 01 , w 02 wrapped around the legs, but are not seated on the legs, nor do they touch the legs).
  • Each one of the two smallest winding units w 0 includes a configuration of turns A1, A2 being equal to approximately two turns w 01 of the primary winding w 1 turns B1, B2 being equal to approximately two turns w 02 of the secondary winding w 2 which are nested in each other as shown.
  • the turns w 01 w 02 are free standing in space, as it were, except for the ends of the smallest winding units which, in the case of the primary winding w 1 , are designated by reference symbols a11, a12 in the branch A1 and with reference symbols a21, a22 in the branch A2.
  • the ends are designated with symbols b11, b12 in the branch B1 and with symbols b21, b22 in the branch B2.
  • the configurations of turns, or the smallest winding units A1, A2; B1, B2 are referred to as branches below.
  • the ends all to a22 of the branches A1, A2 of the primary winding w 1 and the ends b11 to b22 of the branches B1, B2 of the secondary winding w 2 of the smallest winding units w 0 are at the same time terminal ends for connecting an electrical switching circuit; they are pulled through holes at support and terminal points 2 in the support insulators 1.1, 1.2 and "secured" in these holes, i.e. fixed without play. Terminals and leadthroughs which are not shown in FIGS. 1 to 3 are part of this fixation.
  • a primary current 2xi 1 is fed in and then is divided into the partial currents i 1 at each of the two winding branches A1 and A2 of the primary winding w 1 shown in FIG. 1.
  • the primary current follows a path from the lower winding end all to the upper winding end a12: in the case of the second winding branch A2 of the primary winding, as seen in FIG. 3 at the right magnet leg m2, the partial primary current i 1 follows a path from the upper winding end a21 to the lower winding end a22.
  • the two branches B1 and B2 of the secondary winding w 2 are connected in series
  • the first winding branch B1 of the secondary winding w 2 shown in solid black lines, is wound around the magnet leg m4 in a left-handed or counterclockwise helix, as viewed from above, and the partial secondary current i 2 which is indicated by black current arrows also flows through in this direction, to the terminal point or end b12 of the first winding branch B1. Therefore, as seen in FIG.
  • the conductor 1 2 is led around to the outside of the support insulator 1.1 up to the fixed point or end b21 of the second winding branch B2 of the secondary winding w 2 which is located in the lower reaches of the magnet leg m2, as seen in FIG. 3.
  • the second winding branch B2 is wound around the magnet leg m2 in ascending, lefthanded or counterclockwise helixes, and the partial secondary current i 2 indicated by black arrows, also flows through it in this direction to the winding end or terminal and fixed point b22.
  • the associated direction of flux ⁇ 2 is symbolized by solid black arrows. This means that the directions of the flux ⁇ 2 in the left leg m4 and in the right leg m2 coincide; but they are each opposite to the directions or the flux ⁇ 1 .
  • the leading around of the winding conductor 1 1 on the outside of the support insulator 1.2 is indicated in FIG. 3 by the broken line between the terminal points or ends all and a21, since this bridging in the vertical direction is not visible in FIG. 1.
  • the support structure or means H are provided for the retention of the core M1 and of the two support insulators 1.1, 1.2 on a base plate 3 within a container, tank, vessel or the like containing the dielectric fluid, which is not shown in FIGS. 1 to 3.
  • the support structure or means H is formed of a retaining yoke 4 on the cover or deck side and tie rods 6 which push the retaining yoke 4 against the cover or deck side of the core M1, and therefore push the core against the base plate 3.
  • the tie rods 6 pass through holes 7 formed in the base plate 3 which has a rectangular cross section in particular and through holes in the somewhat narrower retaining yoke 4 which also has a rectangular cross section.
  • the tie rods are tightened by means of tightening nuts 8 at two threaded ends thereof.
  • the tightening nuts 8 are equipped with washers 9.
  • the tie rods 6 may be constructed, in particular, as shoulder screws, in which case a separate anti-rotation safety device can be omitted. It is also possible to make the holes 7 in the base plate tapped holes or tapped blind holes, in which case the lower nuts 8 can be omitted.
  • the retaining yoke 4 is formed of a diamagnetic material such as brass or a suitable plastic, such as GFK (fiberglass reinforced plastic), so that no paths for parasitic secondary fluxes can develop.
  • the tie rods or tension rods 6 may be formed of corrosion-resistant steel.
  • the base plate is also formed of insulating material such as Pertinax or acrylic glass.
  • the plate-shaped support insulators 1.1, 1.2 are disposed at the above-mentioned third minimum distance c from the core M1, are parallel to the plane of the wide sides of the core and are fastened to the base plate 3, such as by cementing in the vicinity of lateral surfaces 3.1 of the base plate 3 which is shaded in FIG. 3.
  • the upper ends of the support insulators 1.1, 1.2 may even be interconnected by non-illustrated connecting strips so that a largely rigid insulator structure is formed.
  • the material for the support insulators 1.1, 1.2 is a high-grade insulator such as Pertinax or acrylic glass.
  • FIGS. 1 to 3 already clarifies the principle of the combination of the smallest winding units w 0 .
  • Each of the winding units is formed of at least one undervoltage and at least one overvoltage winding configuration in the form of the branches A1, B1 and A2, B2.
  • the primary turns w 01 and secondary turns w 02 of these branches which are mutually adjacent, spaced apart by the first minimum spacing a and parallel to each other, envelope the associated magnet leg m4 or m2, as seen in the axial direction of the winding helix.
  • FIG. 4 a rectangular core with the two mutually opposite shorter legs m1, m3 and the mutually opposite longer legs m2, m4 is provided, including the central window cutout 5.
  • Each one of the two longer legs m2, m4 supports three smallest winding units w 0 having primary turns w 01 and secondary turns w 02 which are each wound bifilarly or doubly around the magnet legs at a mutual spacing a and at a distance b from the magnet legs.
  • Each winding unit w 0 has two primary turns w 01 and two secondary turns w 02 , and the series-connected primary turns w 01 for each winding unit w 0 are again referred to as winding branches or "branches" for short and are designated with reference symbols A1 to A6 in the case of the winding branches on the primary side and with reference symbols B1 to B6 in the case of the winding branches on the secondary side.
  • the turns are not shown in detail it goes without saying that they are disposed in the same manner as the rest of the winding units.
  • the winding branch A1 on the primary side has the two winding ends a11, a12
  • the winding branch B1 disposed bifilarly to or doubly-wound with the winding branch A1 has the two winding ends (or starts) b11, b12.
  • the designation of all of the other five smallest winding units w 0 is carried out in such a way that the smallest winding unit w 0 to which the winding branches A6 and B6 belong has winding ends a61, a62 on the primary side and winding ends b61, b62 on the secondary side.
  • the white or clear outlined current arrow i 1 within the primary turns w 01 and the solid black current arrows i 2 within the secondary turns w 02 are shown for the two lower winding units. It is obvious, when viewed from below, that the primary turns w 01 of the left leg m4 are ascending, right-handed helixes and that the partial primary current i 1 also flows through them in this sense, resulting in the flux direction ⁇ 1 indicated by the clear or white arrows according to the screw rule, whereas the secondary turns w 02 , when viewed from above, are descending, right-handed helixes and the partial secondary current i 2 also flows through them in this sense, resulting in the flux direction ⁇ 2 indicated by the solid block arrows opposite to the flux direction ⁇ 1 .
  • the primary and secondary turns w 01 , w 02 are disposed and oriented in such a way that the fluxes ⁇ 1 and ⁇ 2 linked to them and resulting from the partial currents i 1 and i 2 flowing through them, have the same direction in the circulatory sense of the core M2 as the fluxes in the left leg m4, which is a natural conclusion when looking at the right half of FIG. 4 and applying the screw rule.
  • the configuration according to FIG. 4 is much more versatile than that according to FIGS.
  • the pulse transformer can be operated as a voltage transformer or as a current transformer.
  • the winding ends a11 to a62 and b11 to b62 are again conducted through cutouts or holes which are not shown in FIG. 4, in the support insulators and are fixed therein, with appropriate non-illustrated terminals to be provided on the outside.
  • the pulse transformer with the construction according to FIGS. 1 to 3 or FIG. 4 or with a construction as a ring core transformer is shown in FIGS. 7 and 8 and which is yet to be described, is housed in a hermetically closed tank 10 filled with transformer oil or with fluoridated hydrocarbons as a liquid, cooling dielectric 11.
  • the core M3 is a rectangular core that is held centrally inside the tank 10. The core is held by perforated corner brackets 12, only four of which are visible in the illustration according to FIG.
  • non-illustrated tie rods or the like by an upper and a lower base plate, by non-illustrated tie rods or the like, and by the two support insulators 1.1, 1.2, each of which are located on a broad side of the core M3.
  • more non-illustrated corner brackets or supporting blocks may be coordinated with all of the twelve edges of the cuboid or cubic configuration of the pulse transformer.
  • the perforations in the corner brackets 12 should be provided in such a way as not to hinder the convection flow of the dielectric 11.
  • diagrammatically indicated cooling ribs 13 disposed on the outer surface 10.1 of the tank 10 serve for heat dissipation.
  • the pulse transformer according to FIG. 5 is designated by reference symbol PU as a whole; it is integrated with a pulse generator PE in order to form one assembly.
  • the metal tank 10 of the pulse transformer PU is joined to a metallic housing 14 of the pulse generator PE so as to be metallically conducting and mechanically rigid.
  • FIGS. 5 and 6 A comparison of FIGS. 5 and 6 reveals that the winding terminals a11 and a22 of the primary winding w 1 are in metallically conducting contact with the outer or surface wall 10.2 of the tank 10 at contact points 140, and that the upper or high terminal b22 of the secondary winding w 2 is led to the outside through an opposite outer or surface wall 10.3 while being insulated from high-voltage by means of a high-voltage leadthrough 15.
  • the other winding end b11 of the secondary winding w 2 can also be metallically conductingly connected to the outer or surface wall 10.3 if grounded, or else if the secondary winding is not grounded, it can also be led to the outside through a lead-through insulator 15 which is secured against high voltage. Therefore, the leadthrough 15 of the winding terminal b11 is shown in broken lines.
  • the pulse generator PE contains a Blumlein circuit the rectangular, metallic housing 14 of the pulse generator is connected to the tank 10 as mentioned above and is divided into two chambers 16a and 16b.
  • the chamber 16a contains metallic capacitor plates 2/3* having a U shape and a capacitor plate 4/4* disposed between the legs of the U, while the outer metallic housing forms a capacitor coating or capacitor plate 1/1*.
  • These designations 1/1*, 2/3* and 4/4* coincide with the designations 1* and 2* of a first strip line capacitor C K of FIG. 6.
  • the Blumlein circuit for pulse-generating networks is known in the art and is shown and described in detail, for instance in publication (2) or in publication (10) as listed below.
  • a thyratron TH Serving as a quick high-voltage switching path or contact break distance is a thyratron TH, having an anode 17 which according to FIGS. 5 and 6, is connected to the plate or coating 2/3* that is common to both strip line capacitors C K and C F .
  • the anode passes through another high-voltage leadthrough 15 in a partition wall 16c; the cathode, on the other hand, is connected to the metallic housing wall 16d of the chamber 16b, and the chamber 16b is again grounded, as seen by the diagrammatically illustrated terminal B at ground potential.
  • the high voltage HV is fed through a high-voltage line 18 passing through the metallic wall 16d of the chamber 16b, by means of another leadthrough 15.1 and is connected to the anode at a node 18.1.
  • a pulse-generating network PEN of the pulse generator PE contained in the chamber 16a and formed by the housing wall 16 operates with water or with an ethylene/glycol/water mixture or even with pure ethylene glycol as a dielectric 110 and is charged by a non-illustrated pulse charger.
  • the connection to ground potential is again designated with reference symbol B
  • the connection to the high-voltage source is designated with reference symbol HV
  • the ("lower") bus that is normally at ground potential is designated with symbol 19
  • the ("upper") bus that is normally at high-voltage potential is designated with symbol 20.
  • an X-ray flash tube RR is provided as a load of the secondary winding w 2 of the pulse transformer PU, the transformation ratio u being 3, for example, which means that a high-voltage pulse of 30 kV, for example, originating at the primary winding w 1 is stepped up to three times this value by the pulse transformer, i.e. to about 90 kV; this high-voltage pulse is fed to the X-ray flash tube RR which generates high-intensity X-ray pulses in the submicrosecond range.
  • FIGS. 7 and 8 show a pulse transformer with ring core M4 and three smallest winding units w 0 having two turns w 01 and w 02 each.
  • a star-shaped conductor 21, disposed in the projection of the window opening 5 of the ring core M4, is connected to the ends or starts a11, a21, a31 of the primary branches A1, A2, A3, while an outer annular conductor 22 is connected to the ends of the respective primary branches at a12, a22 and a32.
  • a neutral point of the primary winding w 1 is designated by reference symbol aO. It may be seen that a11 three primary branches A1, A2, A3 are mutually parallel.
  • two plate-shaped support insulators 1.1, 1.2 are spaced at a distance c from the wide sides of the ring core M4 and are connected in a suitable manner to the base plate 3 and to each other, while the transformer tank, the liquid dielectric and the high-voltage leadthroughs are omitted in this case as in FIGS. 1 and 3; it goes without saying that these elements may be constructed as shown in FIG. 5.
  • Inserted between the ring core M4 and the support insulators 1.1, 1.2 are spacer blocks 23 of insulating material which, as seen in FIG. 7, are disposed in the gaps between the smallest winding units w 0 .
  • the spacer blocks 23 are only dynamically shown in FIG. 7.
  • Pulse generators with rotation-symmetrical, pulse-generating networks can be constructed with the ring core pulse transformer according to FIGS. 7 and 8, and the least possible contact inductances on a cylindrical current return on the switching element TH or F seen in FIGS. 5 and 6 can be provided.
  • ends a i1 , a i2 and a k1 , a k2 , respectively, of two primary winding branches A i , A k are supported by the support insulator 1.2. All of the individual primary turns w 01 are connected in series, although the wiring connections are not shown.
  • the high-current secondary winding w 2 with its turns w 02 and its secondary winding branches B 1 and B k is supported by the support insulator 1.1.
  • the high-current secondary winding w 2 may include smallest winding units, all of which are mutually parallel or at least mutually parallel in groups.
  • FIG. 9 in conjunction with FIG. 10 shows an oval core M5 which is an elongated oval.
  • An elongated oval, preferably of highly permeable material, of the C-core or tape-wound core type is particularly recommended.
  • the tape-wound core M5 is supported by a solid steel support 24 so as to be fixed in relation to the windings w 1 w 2 . This rigid retention is important because of the high current forces.
  • reference symbol b i2 for the lower leg m6 and with reference symbo b k2 for the winding end of the secondary winding parts on the upper leg m5 while reference numeral b 0 designates a common terminal for the incoming and outgoing currents of the secondary winding w 2 .
  • the current terminals b i2 , b k2 and b 0 permit a predominantly bifilar or doubly-wound connection to the load through non-illustrated strip conductors. It is possible with this current transformer configuration to provide ohmic resistances in the secondary winding w 2 of several ⁇ Ohms and current pulses of several Megaamperes.
  • the high-current winding which is constructed of rectangular conductor tubes 1 20 , may be flushed by a liquid coolant in order to carry away the copper losses serially, or in series-parallel connection, or with the cooling paths of each individual turn parallel to each other, depending on the capacity.
  • the same may be applied analogously to the high-voltage winding w 1 for the primary side, the copper conductors of which are designated with reference symbol 1 10 .
  • the primary and secondary windings w 1 , w 2 are cooled from both the inside with liquid coolant (especially water) and the outside by the cooling action of the dielectric which, at higher capacities and/or with more viscous dielectrics, may be circulated by a pump.
  • liquid coolant especially water

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Plasma & Fusion (AREA)
  • Optics & Photonics (AREA)
  • Coils Or Transformers For Communication (AREA)
  • Coils Of Transformers For General Uses (AREA)
  • Superconductors And Manufacturing Methods Therefor (AREA)
  • Transformer Cooling (AREA)
  • Regulation Of General Use Transformers (AREA)
  • Power Conversion In General (AREA)
  • Insulating Of Coils (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
  • Particle Accelerators (AREA)
US06/898,707 1985-08-21 1986-08-21 High-power pulse transformer for short high-voltage and/or high-current pulses Expired - Fee Related US4763093A (en)

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Cited By (20)

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DE3831610A1 (de) * 1988-09-17 1990-03-22 Ceag Licht & Strom Schaltnetzteil
US5023585A (en) * 1988-11-17 1991-06-11 Murata Manufacturing Co., Ltd. Common-mode choking coil
US5138622A (en) * 1988-04-20 1992-08-11 Siemens Aktiengesellschaft Apparatus and method for generating high-power, high-voltage pulses, particularly for te gas lasers
US5304850A (en) * 1991-01-18 1994-04-19 Kyong Sun Jun Power line carrier frequency breaker
US5422619A (en) * 1991-08-20 1995-06-06 Murata Manufacturing Co., Ltd. Common mode choke coil
US5508673A (en) * 1993-06-02 1996-04-16 Alcatel Network Systems, Inc. High frequency transformer apparatus
US6090350A (en) * 1996-02-16 2000-07-18 Wave Separation Technologies, Llc System for separating constituents from a base material
WO2000069035A1 (en) * 1999-05-07 2000-11-16 Lambda Physik Ag Coaxial laser pulser with solid dielectrics
WO2001033909A2 (en) * 1999-11-03 2001-05-10 Nexicor Llc Hand held induction tool
US20020015430A1 (en) * 2000-05-15 2002-02-07 Lambda Physik Ag Electrical excitation circuit for a pulsed gas laser
US20020140464A1 (en) * 2000-05-03 2002-10-03 Joseph Yampolsky Repetitive power pulse generator with fast rising pulse
US20040119577A1 (en) * 2002-12-20 2004-06-24 Robert Weger Coil arrangement with variable inductance
US6834066B2 (en) 2000-04-18 2004-12-21 Lambda Physik Ag Stabilization technique for high repetition rate gas discharge lasers
US20050225193A1 (en) * 2004-04-07 2005-10-13 Yue-Chung Chen Mike 4001 design of the stator of electrical motor & generator
US20060163971A1 (en) * 2005-01-21 2006-07-27 Magnetic Power Inc. Solid state electric generator
US20070071047A1 (en) * 2005-09-29 2007-03-29 Cymer, Inc. 6K pulse repetition rate and above gas discharge laser system solid state pulse power system improvements
US20080218300A1 (en) * 2004-09-24 2008-09-11 Koninklijke Philips Electronics, N.V. Transformer
US7616088B1 (en) * 2007-06-05 2009-11-10 Keithley Instruments, Inc. Low leakage inductance transformer
US20130314196A1 (en) * 2012-05-25 2013-11-28 Hitachi Industrial Equipment Systems Co., Ltd. Wound Core Scot Transformer
US20170323717A1 (en) * 2016-05-05 2017-11-09 Ut Battelle, Llc Gapless core reactor

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DE19708311C1 (de) * 1997-02-28 1998-05-07 Werner Grose Vorrichtung einer modularen Schaltungs- und Übertragungseinheit für die elektrostatische Perforation

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Cited By (37)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5138622A (en) * 1988-04-20 1992-08-11 Siemens Aktiengesellschaft Apparatus and method for generating high-power, high-voltage pulses, particularly for te gas lasers
DE3831610A1 (de) * 1988-09-17 1990-03-22 Ceag Licht & Strom Schaltnetzteil
US5023585A (en) * 1988-11-17 1991-06-11 Murata Manufacturing Co., Ltd. Common-mode choking coil
US5304850A (en) * 1991-01-18 1994-04-19 Kyong Sun Jun Power line carrier frequency breaker
US5422619A (en) * 1991-08-20 1995-06-06 Murata Manufacturing Co., Ltd. Common mode choke coil
US5508673A (en) * 1993-06-02 1996-04-16 Alcatel Network Systems, Inc. High frequency transformer apparatus
US6090350A (en) * 1996-02-16 2000-07-18 Wave Separation Technologies, Llc System for separating constituents from a base material
WO2000069035A1 (en) * 1999-05-07 2000-11-16 Lambda Physik Ag Coaxial laser pulser with solid dielectrics
US6198761B1 (en) 1999-05-07 2001-03-06 Lambda Physik Gmbh Coaxial laser pulser with solid dielectrics
WO2001033909A3 (en) * 1999-11-03 2001-12-13 Nexicor Llc Hand held induction tool
US6509555B1 (en) 1999-11-03 2003-01-21 Nexicor Llc Hand held induction tool
US6639198B2 (en) 1999-11-03 2003-10-28 Nexicor Llc Hand held induction tool with energy delivery scheme
US6639197B2 (en) 1999-11-03 2003-10-28 Nexicor Llc Method of adhesive bonding by induction heating
US20040050839A1 (en) * 1999-11-03 2004-03-18 Riess Edward A. Method of adhesive bonding by induction heating
US6710314B2 (en) 1999-11-03 2004-03-23 Nexicor Llc Integral hand-held induction heating tool
WO2001033909A2 (en) * 1999-11-03 2001-05-10 Nexicor Llc Hand held induction tool
US6849837B2 (en) 1999-11-03 2005-02-01 Nexicor Llc Method of adhesive bonding by induction heating
US6834066B2 (en) 2000-04-18 2004-12-21 Lambda Physik Ag Stabilization technique for high repetition rate gas discharge lasers
US20020140464A1 (en) * 2000-05-03 2002-10-03 Joseph Yampolsky Repetitive power pulse generator with fast rising pulse
US6831377B2 (en) * 2000-05-03 2004-12-14 University Of Southern California Repetitive power pulse generator with fast rising pulse
US6862307B2 (en) 2000-05-15 2005-03-01 Lambda Physik Ag Electrical excitation circuit for a pulsed gas laser
US20020015430A1 (en) * 2000-05-15 2002-02-07 Lambda Physik Ag Electrical excitation circuit for a pulsed gas laser
US20040119577A1 (en) * 2002-12-20 2004-06-24 Robert Weger Coil arrangement with variable inductance
US20050225193A1 (en) * 2004-04-07 2005-10-13 Yue-Chung Chen Mike 4001 design of the stator of electrical motor & generator
US7474031B2 (en) * 2004-04-07 2009-01-06 Yue-Chung Chen Mike 4001 design of the stator of electrical motor and generator
US20080218300A1 (en) * 2004-09-24 2008-09-11 Koninklijke Philips Electronics, N.V. Transformer
US7932799B2 (en) 2004-09-24 2011-04-26 Koninklijke Philips Electronics N.V. Transformer
US7830065B2 (en) * 2005-01-21 2010-11-09 Chava LLC Solid state electric generator
US20060163971A1 (en) * 2005-01-21 2006-07-27 Magnetic Power Inc. Solid state electric generator
WO2007041232A3 (en) * 2005-09-29 2007-12-13 Cymer Inc 6k pulse repetition rate and above gas discharge laser system solid state pulse power system improvements
WO2007041232A2 (en) * 2005-09-29 2007-04-12 Cymer, Inc. 6k pulse repetition rate and above gas discharge laser system solid state pulse power system improvements
US20090238225A1 (en) * 2005-09-29 2009-09-24 Cymer, Inc. 6K pulse repetition rate and above gas discharge laser system solid state pulse power system improvements
US20070071047A1 (en) * 2005-09-29 2007-03-29 Cymer, Inc. 6K pulse repetition rate and above gas discharge laser system solid state pulse power system improvements
US7616088B1 (en) * 2007-06-05 2009-11-10 Keithley Instruments, Inc. Low leakage inductance transformer
US20130314196A1 (en) * 2012-05-25 2013-11-28 Hitachi Industrial Equipment Systems Co., Ltd. Wound Core Scot Transformer
US20170323717A1 (en) * 2016-05-05 2017-11-09 Ut Battelle, Llc Gapless core reactor
US10504645B2 (en) * 2016-05-05 2019-12-10 Ut-Battelle, Llc Gapless core reactor

Also Published As

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JPS6254412A (ja) 1987-03-10
EP0215286B1 (de) 1990-03-14
DE3669625D1 (de) 1990-04-19
JPH033365B2 (de) 1991-01-18
AU6165686A (en) 1987-02-26
AU568250B2 (en) 1987-12-17
CA1260088A (en) 1989-09-26
EP0215286A1 (de) 1987-03-25
ATE51112T1 (de) 1990-03-15

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